A major program in our laboratory revolves around the purification and characterization of 22 interferon alpha components that were isolated in our laboratory. Many of the components are very similar in their amino acid composition, amino terminal sequences, apparent molecular weight, and antiviral, antiproliferative and immunomodulatory specific activities; yet, some differ in one, two or several of the above mentioned properties. In addition, three components have been found to have high level of carbohydrate attached to the protein molecule (glycosylation) of the component . Currently, we are focusing on the nature of the linkages of the carbohydrate moiety to the protein backbone. The role of the carbohydrate associated with the glycosylated interferon components has yet to be determined; however,our previous studies have shown that the interferon components play a major role in modulating many diverse cellular responses. We are continuing our receptor binding studies , cloning and gene expression inorder to better understand those responses. Interferon is one of the cytokines which are being reviewed by the Division. Through this research, we hope to learn more about the manner in which interferon binds to cells prior to exhibiting its various actions (anti-proliferatve, anti-viral). Knowledge of its mode of action is critical if we are to more fully understand the many applications for which interferon is used and for which it may be proposed. Using the technology to create constructs in the laboratory have led to a better understanding of the regulatory issues of new IFN constructs currently in drug development.